The cold snap is due to a "polar vortex," which is basically a cyclone of air from the North Pole (thanks, Santa). Those aren't uncommon, but this time, due to a "relatively infrequent alignment of weather conditions," the vortex will move unusually far south over the next two days.

Starting yesterday and continuing into today and Tuesday, temperatures could drop as low as -30 in northern Minnesota, with a wind chill of -70. Several areas of the Midwest aren't expected to post a daily high above zero, something that's only happened a few times in Detroit and Cincinnati since the 1870s. It's expected that temperatures will be the coldest those areas have seen in decades.

Not even Florida will be spared, as while the southern tip is looking at lows of 69 degrees on Monday, by Tuesday it'll be 46, with upper parts of the state in the low 20s. That's downright tropical compared to Atlanta, which is expecting single-digit and even subzero temperatures.

The good news is, the polar vortex will move on soon, and by Thursday we should be back to our cold normal.